Substantial work has been done in the past concerning automatic monitoring and control of conventional flush toilets. See for example commonly-assigned U.S. Pat. No. 8,704,671 (“Self-stick resonant enclosure that responds to flush toilet fill valve water inflow vibration”); U.S. Pat. No. 8,362,907 (“Self-stick resonant enclosure that responds to flush toilet fill valve water inflow vibration”); U.S. Pat. No. 8,310,369 (“Detecting unintended flush toilet water flow”); U.S. Pat. No. 8,166,996 (“Toilet bowl overflow prevention and water conservation system and method”); U.S. Pat. No. 7,757,708 (“Toilet bowl overflow prevention and water conservation system and method”), all incorporated herein by reference.
Further improvements are possible.
In one example non-limiting embodiment herein, a toilet monitor comprises a toilet tank water level sensor producing a toilet tank water level measurement signal. A processor is connected to receive the measurement signal. The processor detects the rate of change of the measurement signal and conditionally produces a responsive actuation signal in response to the detected rate of change. A transducer is connected to receive the actuation signal.
Further example non-limiting features include:                The processor may evaluate a sequence of rates of change to detect toilet operation abnormalities.        The processor detects predetermined sequences of rates of change. The processor detects rate of change using a rolling block interval analysis.        The processor uses a linear equation to analyze the rate of change measurement signal.        The processor determines an anomaly in water flow within the toilet bowl based on the rate of change of the toilet tank water level measurement signal.        The processor determines the toilet is leaking in response to the rate of change.        The processor determines the toilet is leaking by tracking the direction and/or the cycles of the rate of change.        The processor determines the toilet fill valve is defective in response to the rate of change.        The processor determines the toilet fill valve is defective by tracking the direction of the rate of change followed by the absence of rate change.        The processor determines the toilet flush valve is open in response to the rate of change.        The processor determines the toilet flush valve is open by tracking the absence of the rate of change.        The processor determines current and/or imminent toilet overflow in response to the rate of change.        The processor determines toilet overflow based on magnitude of rate of change.        The processor detects fluid volume usage based on rate of change.        The processor detects the prolonged absence of double flushes.        The sensor is configured for placement within a toilet tank, the water level sensor producing a measurement signal indicating the level of fluid within the toilet tank.        The transducer comprises at least one of (a) a valve, (b) an optical indicator, (c) an audible sound generator, and (d) a transmitter.        The water level sensor comprises a capacitive sensor but could be any type of water level sensor. The disclosed processes thus could work with a different type of sensor.        The capacitive sensor comprises first and second conductors, the first conductor being covered by an insulator.        The processor logs the rate of change for later retrieval and water usage tracking.        The sensor is configured to be disposed inside the tank and has a length that is less than the extent of the water level change within the tank, and the processor uses the measurement signal to extrapolate the measurements based on the extent of the water level change within the tank.        The processor is configured to sleep and to wake up at time intervals to sample the rate of change.        The toilet tank monitor is battery powered and has no on/off switch.        
In another non-limiting embodiment, a toilet monitor comprises a toilet tank water level sensor producing a toilet tank water level measurement signal. A processor is connected to receive the measurement signal. The processor detecting the presence or absence of plural successive flushes within a predetermined time period based on the measurement signal and generating an actuation signal to affect toilet tank flush volume. A valve is connected to receive the actuation signal. The valve increasing or decreasing toilet tank flush volume.
In another non-limiting embodiment, a toilet monitor comprises a toilet tank water level sensor producing a toilet tank water level measurement signal. An electronic circuit is connected to receive the measurement signal. The electronic circuit determines an anomaly in water flow within the toilet bowl based on the toilet tank water level measurement signal.